Gov. Jerry Brown on Friday signed a bill that is expected to reduce the cost of expensive special elections in San Diego County by offering all voters mail-in ballots and limiting polling places.

Assembly Bill 1873 was carried by Assemblywoman Lorena Gonzalez, D-San Diego, on behalf of San Diego County government leaders.

It creates a five-year pilot project for county government, which could conduct any special election for a vacancy in Congress or the state Legislature through a vote-by-mail process. Special elections take place to fill offices that are left vacant, often unexpectedly.

Under the law, every registered voter will be mailed a ballot with return postage paid during a special election.

Voters would also have the chance to vote in person — either at an early voting location the weekend before Election Day or on Election Day at a limited number of polling places, according to a press release from Gonzalez.

Special elections where all polling places are staffed can cost jurisdictions millions of dollars and often result in low voter turnout. Unlike statewide elections, the county is not reimbursed for the cost of special elections by the state.

Local agencies already have the ability to conduct local special vacancy elections by vote-by-mail.

This is the first time congressional or legislative races could be conducted in this way, after years of efforts by the county to accomplish the feat.

“As elected officials, we have a responsibility to address the plummeting voter turnout and high taxpayer costs we’ve seen in recent special elections,” Gonzalez said in a statement. “AB 1873 creates a program that makes voting more accessible and elections cheaper while protecting the integrity of the voting process.”